This study will be carried out as an ancillary project to the NIH Neonatal Network multicenter, randomized, double masked clinical trial "Dexamethasone Therapy in Very Low Birthweight Infants at Risk for Chronic Lung Disease". A standardized dosing regimen of dexamethasone and placebo will be employed in the large multicenter trial and will test for the efficacy and side effects of dexamethasone therapy in the prevention of chronic lung disease in a population of at risk preterm infants.